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Overview
| Comment: | Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | multikey-opt-idea |
| Files: | files | file ages | folders |
| SHA3-256: |
87a9fc504f9a78caf7a7949cc7ada0a1 |
| User & Date: | drh 2018-06-05 15:16:25 |
Context
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2018-06-05
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| 20:45 | Add the OP_IfNoHope and OP_SeekHit opcodes used to reduce the number of unnecessary sqlite3BtreeMovetoUnpacked() calls when checking for an early exit on IN-operator loops. Futher optimizations are likely possible here. check-in: 6bf251af user: drh tags: multikey-opt-idea | |
| 15:16 | Use an OP_NotFound opcode to cancel futile IN operators early. The current implementation is suboptimal because it always runs teh OP_NotFound. This still needs to be enhanced to only do the OP_NotFound if no results have been seen on the current loop. check-in: 87a9fc50 user: drh tags: multikey-opt-idea | |
| 13:54 | Merge trunk changes. check-in: 047295c5 user: drh tags: multikey-opt-idea | |
Changes
Changes to src/where.c.
5080 5080 struct InLoop *pIn; 5081 5081 int j; 5082 5082 sqlite3VdbeResolveLabel(v, pLevel->addrNxt); 5083 5083 for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){ 5084 5084 sqlite3VdbeJumpHere(v, pIn->addrInTop+1); 5085 5085 if( pIn->eEndLoopOp!=OP_Noop ){ 5086 5086 if( pIn->nPrefix ){ 5087 - sqlite3VdbeAddOp3(v, OP_Noop, pLevel->iIdxCur, 5087 + sqlite3VdbeAddOp4Int(v, OP_NotFound, pLevel->iIdxCur, 5088 + sqlite3VdbeCurrentAddr(v)+2, 5088 5089 pIn->iBase, pIn->nPrefix); 5090 + VdbeCoverage(v); 5089 5091 } 5090 5092 sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop); 5091 5093 VdbeCoverage(v); 5092 5094 VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen); 5093 5095 VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen); 5094 5096 } 5095 5097 sqlite3VdbeJumpHere(v, pIn->addrInTop-1);
Changes to src/wherecode.c.
588 588 int iCol = aiMap ? aiMap[iMap++] : 0; 589 589 pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut); 590 590 } 591 591 sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v); 592 592 if( i==iEq ){ 593 593 pIn->iCur = iTab; 594 594 pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen; 595 - pIn->iBase = iReg - i; 596 - pIn->nPrefix = i; 595 + if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ){ 596 + pIn->iBase = iReg - i; 597 + pIn->nPrefix = i; 598 + }else{ 599 + pIn->nPrefix = 0; 600 + } 597 601 }else{ 598 602 pIn->eEndLoopOp = OP_Noop; 599 603 } 600 604 pIn++; 601 605 } 602 606 } 603 607 }else{